Thanks Sendler, I am aware of it's function. I just wanted to know how much heat it generates as a driver chip. In this application the driver chip is sandwiched between two boards and has no air circulation. Even a little heat can build up so I asked the question. Do you have any idea. Thanks
Terry
Ferroxcube cores
If those are the Dumbos, are these Ferroxcube cores the mice? Less opaque than the T106-2 cores. Easier to wind than the air cores. A little aggressive sounding though. Maybe could use a couple more turns. These are nine turns for 8uH. I wish I could get a hold of the next bigger size. Man, that 14ga Belden is stiff and hard to strip.
If those are the Dumbos, are these Ferroxcube cores the mice? Less opaque than the T106-2 cores. Easier to wind than the air cores. A little aggressive sounding though. Maybe could use a couple more turns. These are nine turns for 8uH. I wish I could get a hold of the next bigger size. Man, that 14ga Belden is stiff and hard to strip.
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Anybody using this amp with Maggie MMG's? Seems like it might make a good match. I just got my Superphon preamp and am listening to the Sure board fed by an Oppo 981HD into a brand new Beresford TC-7520 DAC. But my back-loaded horns with Fostex FE166E drivers are a bit oversensitive to the fairly high power this amp puts out.
I use a floating preregulator in front of the board that
a) takes away most of the heat and can be heatsinked separately and
b) works beautifully to bring down the noise to the level I find on the ground rail
Schematic is attached: the top bit is the prereg and the lower bit is the mod on the board where I basically replaced R2 and R3 by LEDs, a cap and a 470 Ohm resistor.
Also attached is a picture of the mod I did on the wiring to bring out the power supply for the regulator separate from the power supply of the driver chips.
Attachments
I've just ordered one of these boards, I'm guessing these should sound similar to a TA2020 amp but with more power?
After reading thru the entire thread, I guess the whole output inductor/zobel resistor thing depends a lot of what speakers and the impedance of any passive XO circuit (if any?).
Is anyone using this board in a bi-amp type set up, with 1 amp channel per speaker driver? I was hoping to use this amp to drive 2 x 4R woofers, which will be used from 40Hz-2.7KHz, so would it be worth experimenting with different values for the output inductors and zobel network as I'm not really concerned about frequency response above 5KHz or so.
After reading thru the entire thread, I guess the whole output inductor/zobel resistor thing depends a lot of what speakers and the impedance of any passive XO circuit (if any?).
Is anyone using this board in a bi-amp type set up, with 1 amp channel per speaker driver? I was hoping to use this amp to drive 2 x 4R woofers, which will be used from 40Hz-2.7KHz, so would it be worth experimenting with different values for the output inductors and zobel network as I'm not really concerned about frequency response above 5KHz or so.
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I must confess I only made it to page 10 before I wrote the above... I could not find the edit button so excuse this double post.
Dr Vega, I don't suppose you could give me some more info about your bi-amped setup? I'm also using a DCX2496 as an active XO, and while it works well, I'm also having to use a 4-gang pot as a volume control. Is your DCX2496 modded in any way?
Right now my setup consists of:
source -> DCX2496 > 4 gang-pot > 2 x Lepai TA2020 amps with tone controls bypassed > speakers with 4gang speakon connectors.
I was using a 41Hz.com amp9 along with the meanwell 350W 42v PSU, but recently 2 out of the 4 channels stopped working!
I'm thinking I can mount the amps inside the speakers, and just have 3 pin XLR connectors going to the amps, and lose the speaker wires (and speakons). I'm tempted to mount the PSU in the speaker also, and have a seperate PSU for each amp, I can even put IEC sockets on each speaker, giving quite a nice active speaker!
I must confess I only made it to page 10 before I wrote the above... I could not find the edit button so excuse this double post.
Dr Vega, I don't suppose you could give me some more info about your bi-amped setup? I'm also using a DCX2496 as an active XO, and while it works well, I'm also having to use a 4-gang pot as a volume control. Is your DCX2496 modded in any way?
Right now my setup consists of:
source -> DCX2496 > 4 gang-pot > 2 x Lepai TA2020 amps with tone controls bypassed > speakers with 4gang speakon connectors.
I was using a 41Hz.com amp9 along with the meanwell 350W 42v PSU, but recently 2 out of the 4 channels stopped working!
I'm thinking I can mount the amps inside the speakers, and just have 3 pin XLR connectors going to the amps, and lose the speaker wires (and speakons). I'm tempted to mount the PSU in the speaker also, and have a seperate PSU for each amp, I can even put IEC sockets on each speaker, giving quite a nice active speaker!
My setup is pretty conventional, a lot like what you are proposing.
I come out of a Pioneer DV562A DVD/CD/SACD player to a dbx 386 hybrid tube preamp to the Behringer DCX2496 to 3 Sure amps, one for each two-way main and one for a DVC subwoofer.
Sometimes I run digital directly from the Pioneer to the Behringer, bypassing the dbx, but I ususally include the tubes. They add a nice ambience.
The Pioneer is stock, the dbx and Behringer have all their caps upgraded and the DCX has the unbalanced passive output mod. I tried a 6-gang Alps volume control after the DCX, but it took all the life out of the music. So I use the dbx for volume control. I know that is supposed to be bad, but it sounds better to me than the pot did.
I pulled apart an 8 foot XLR to RCA snake to get my interconnects - definitely mid-fi.
My speakers are diy open baffles, so the amps mount directly on the back of the baffles and feed the speaker through 6" Cat 5e cables.
I use a separate brick smps for each amp: 34V for the mains, 36V for the sub. All the bricks are from HP and Kodak laser printers and provide about 3 amps. I got all of them new on ebay for less than $20 each.
I mostly listen to vocal jazz, blues, classic rock, and doo wop. Occassionally I listen to Beethoven, Charles Ives and a few other classicals.
My local audiophile club, while skeptical about all the digital in the audio path and the smps, grudgingly admit the setup sounds pretty damn good. I'm very pleased with it, although I still have some more upgrades to do on the amps and I want to try air core inductors.
I work with jazz combos (3 to 8 piece bands) in unamplified settings, so I know what a saxophone and a trumpet really sound like. My system is beginning to please me well.
-dr_vega
dr. Vega, on the Cat5e cables: how did you connect them up? I would image you tied all the 'whites' together and all the solid colors and run your signal through all 4 pairs?
2nd question on the 4X100Watt amplier from sure. can the same front end changes be made on that amp? Such as the input cap? I thinking about buying that amp and modding it also.
Thanks!
2nd question on the 4X100Watt amplier from sure. can the same front end changes be made on that amp? Such as the input cap? I thinking about buying that amp and modding it also.
Thanks!
I wired the Cat 5: solids +; and stripes -. I don't think it's critical for this short distance.
All Tripath chip amps have the same basic architecture and benefit from the same mods. In the case of the Sure 4X100, it's pretty much two 2x100s on the same board and sharing the power supply. All the same mods apply.
-dr_vega
Measurements while powering amp?
I wonder what the scope pattern would look like with the power supply actually powering the amp at high listening volume and with the supply outputs left floating as in the poor example? Would the amp pull the negative supply leg to audio ground and stabilize it with out the need for the jumper? It would also be interesting to see if the music power demand can modulate the supply at all. The MeanWell supplies sound very stiff to me.
I have to re-do this measurement anyway as I found myself unable to repeat the results the other day. I suspect a grounding (or rather floating) issue with the scope.
Will be a few days, though, as I am currently travelling.
What do you guys make of this "warning" from Sure?
I'm using a Superphon Revelation Basic (love it, btw), and it's a bit of a chore to set the volume w/o getting really high volume (95dB speakers), especially since it's a dual-mono preamp. But really, damage because of a high input signal? WTF? Does this even make sense? Unity input is 1 to 2 V if I'm not mistaken in a home audio environment, right? I have the DIP switches set to the lowest setting.
Warning 3:
DO NOT equip a pre-amplifier to the audio input since the amplifier itself has powerful amplification ability and a high signal input will burn out the amplifier chip.
DO NOT equip a pre-amplifier to the audio input since the amplifier itself has powerful amplification ability and a high signal input will burn out the amplifier chip.
I'm using a Superphon Revelation Basic (love it, btw), and it's a bit of a chore to set the volume w/o getting really high volume (95dB speakers), especially since it's a dual-mono preamp. But really, damage because of a high input signal? WTF? Does this even make sense?
Unity input is 1 to 2 V if I'm not mistaken in a home audio environment, right? I have the DIP switches set to the lowest setting.TC2000 driver chip is fragile
The TC2000 driver chip is fragile to pops or mistakenly hi inputs. There is a protection zener across the inputs of the Sure but most of us have removed it for a slight improvement in sound. Tripath claims max inputs of 2.5v or beyond can damage the chip. This is way beyond full power from the amp so no one would intentionally crank their pre up that far but accidents happen. Sure is just warning you as to the failures they have seen so your mistake doesn't have to become their problem when the amp blows on the first power up. A tube pre can put out 10 or 15v when cranked.
What do you guys make of this "warning" from Sure?
Warning 3:
DO NOT equip a pre-amplifier to the audio input since the amplifier itself has powerful amplification ability and a high signal input will burn out the amplifier chip.
I'm using a Superphon Revelation Basic (love it, btw), and it's a bit of a chore to set the volume w/o getting really high volume (95dB speakers), especially since it's a dual-mono preamp. But really, damage because of a high input signal? WTF? Does this even make sense?
The TC2000 driver chip is fragile to pops or mistakenly hi inputs. There is a protection zener across the inputs of the Sure but most of us have removed it for a slight improvement in sound. Tripath claims max inputs of 2.5v or beyond can damage the chip. This is way beyond full power from the amp so no one would intentionally crank their pre up that far but accidents happen. Sure is just warning you as to the failures they have seen so your mistake doesn't have to become their problem when the amp blows on the first power up. A tube pre can put out 10 or 15v when cranked.
That makes sense. I had assumed they were covering their collective derrieres, especially after the inadequate heatsink/no fan problems they had. I love the amp, but I am vexed by the squirrely need to keep my volume pots at well under 10:00 o'clock, a setting that is extremely loud on my speakers. I might buy some SMD DACT-like 250 kohm mono pots from VALAB. Or get less efficient speakers . . .
Thanks for your reassuring post, sendler.
Just a quick question about this amp, is it possible to parallel the outputs in order to drive a low impedance load?
The main reason I'm using a pot is because the levels from the XLR's are far to loud unless you have everything turned down -20db, and if I do this I lose resolution within the DCX.
I must admit, a pot isn't really ideal, it only needs a 1/3rd of a turn before the TA2020 amps start to distort, so I'm thinking maybe a stepped attenuator may be the way to go.
Hopefully the tc2000+tp2050 amp should be a good upgrade over a ta2020 amp, it's always nice to have more headroom regardless.
Excellent info, thanks. Do you have anymore info in the unbalanced passive output for the DCX? Does it lower the output level?
The main reason I'm using a pot is because the levels from the XLR's are far to loud unless you have everything turned down -20db, and if I do this I lose resolution within the DCX.
I must admit, a pot isn't really ideal, it only needs a 1/3rd of a turn before the TA2020 amps start to distort, so I'm thinking maybe a stepped attenuator may be the way to go.
Hopefully the tc2000+tp2050 amp should be a good upgrade over a ta2020 amp, it's always nice to have more headroom regardless.
Sendler has good info. Here's some more, some of it in French:
passive output stage for DCX2496
-dr_vega
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